Valve.



PATENTED FEB. 27, 1906.

M. HOGHWALD.

VALVE.

APPLIOATION FILED AUG. 22, 1905.

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MORITZ HOOHWALD, OF BERLIN, GERMANY.

VALVE.

Specification of Letters Patent.

Patented Feb. 27, 1906.

Application filed August 28, 1905. Serial No. 276,112.

To a whom it may concern.-

Be it known that I, MORITZ 'HOGHWALD, a subject of the German Emperor, and a resident of Berlin, Germany, have invented certain new and useful Improvements in Valves, of which the following is a specification.

When the usual double-seat valves are used as regulating-valves for large steam-cylinders, the cross-sectional area of the passage for the steam is insuflicient, and as a consequence when the valve is opened or closed the inflowing or outflowing steam will assume speeds that exceed the permissible limit and cause considerable throttling losses, this being in particular noticeable when the valve mechanism works at a rapid pace. A-

better opening and closing effect is obtained by providing the valve with a plurality of openings or passages, and this was hitherto done by dividing the channel which leads to the interior of the cylinder and increasing the number of valve-seats opening into the interior'channel. The division of the cylinderchannel and the increase of the valve-seats, however, increases the detrimental or dead spaces and also increases the walls, which tend to effect an undesirable condensation of the inflowing steam. It is, moreover, practically impossible to keep the many seat-surfaces tight when high-pressure steam is employed, and there is therefore considerable escape of the steam in four-seat valves and similar valves. When superheated steam is used, it is still more difficult to keep the valve permanently tight.

The present invention has for its object to increase the number of passages without increasing the number of valve-seats and without dividing the interior or cylinder channel of the cylinder.

My improved valve does away with all the drawbacks of the ordinary four-seat valves and similar valves by obtaining an increase of the number of passages without increasing the number of seats toward the interior of the cylinder and without increasing the detrimental or dead space. Moreover, the amount of force necessary for lifting the new valve is not greater than in an ordinary double-seat valve, notwithstanding the increased number of passages, and is considerably smaller than in a four-seat valve.

In the accompanying drawings one embodiment of the invention is shown applied to an inlet double-seat valve.

Figure 1 shows the valve in closed position. Fig. 2 shows the valve partly opened, and Fig. 3 illustrates the working diagram of the new valve as compared with other valves.

The valve is provided with rings which cover the passages and overlap the auxiliary valve-seats. The rings, which may serve known purposes, are in the present instance employed for increasing the passages of the valve. In the embodiment shown in the drawings this object is attained by providing the ordinary double-seat valve with two trough-shaped sliding rings a and b, which when the valve is closed, cover the two openings toward the channel 0, leading from the cylinder toward the exterior, the rings a and b cooperating with the trough-shaped cavities or recesses d in the valve-casing. When the invention is applied to an inlet-valve for steam, as shown in the drawings, the two rings are arranged above the two main valveseats, while they are arranged between the main valve-seats when the invention is applied to an outlet-valve. The seat-lapping portion of the slide-rings corresponds to the width of the seats e. If the valve is elevated a distance approximately corresponding to one of the auxiliary seats 6, steam commences to pass in simultaneously at the four edges f, g, h, and i. In this position,- Fig. 2, the valve is elevated from its main seats a distance corresponding to one of the seats 6, and under the assumption that e is equal to half the valvestroke the entire area of the passages will be open both in the valve and at the circumference of the rings when the stroke is completed. The improved valve therefore presents four passages for the steam in spite of the fact that there are only two seats in the inlet-channel 7c of the cylinder. The same result might also be accomplished in another manner, and n+ ac passages might be obtained ina valve having n seats by providing 01+ x ordinarys lide-rings; but this would necessitate an undesirable height of the valve.

The superior effect of the new valve as compared with other valves will be understood by considering the diagram shown in Fig. 3. The line Zm n indicates a curve of the elevation of the ordinary double-seat valve. In order to attain a steady working of the regulating device, the valve must be elevated and closed at a rather slow pace. The opening and closing is therefore very slow. This drawback is removed to some extent by the arrangement of a lap-closure, in which case the line 0 p m indicates the curve of elevation, and m 1" 8 indicates the closing curve. The opening of the valve-passage commences at p, and a better effect is obtained than in the ordinary valve. The part of the stroke which corresponds to the seat-lapping portion does not, however, become utilized in this valve. In the new valve the curve of elevation likewise passes through 0 p 1" s; but the area of the opening space increases, as p as y z r, by reason of the increased number of passages. Thus it will be seen that the opening and closing of the passages is very sudden. In the initial position and in the closing position of the new valve the area of the opening space is much greater than in the ordinary two-seat valve, and throttling of the steam is therefore avoided. Moreover, in the present invention the lap-closure does not reduce the useful stroke. Finally, the invention presents the advantage of requiring a much smaller eccentricity for a given 0 ening of the valve, and it is therefore posslble not only to obtain better areas of open ing in the interior regulating device, but also smaller ratios of speed in the exterior regulating device, which assures a better distribution of the steam and a steady working of the regulating device.

The invention may also be used in valves having more than two seats. A four-seat valve, for instance, may be provided with six passages by providing three trough-shaped sliding rings.

The valve according to the present invention may be used to advantage not only for steam, but also for any similar driving medium, such as gas.

Having described my invention, what I claim as new therein is 1. The combination of the valve-casing having a main valve-seat, a passage located on one side thereof and a cavity or recess adjacent to the passage; a valve adapted to seat on the main seat; and a troughshaped ring positioned to cover the passage and overlap its walls when the main valve is closed and to connect the passage with the cavity after the main valve is open.

2. The combination of the valve-casing having a main valve-seat, a plurality of passages located on one side thereof, and a recess or cavity adjacent each passage; a valve adapted to seat on the main seat; and a plurality of trough-shaped members positioned to cover the passages when the main valve is closed and to connect the passages with the recesses or cavities after the main valve is open.

In testimony whereof I afliX my signature in presence of two witnesses.

MORITZ HOCHWALD.

Witnesses:

WOLDEMAR HAUPT, WILLIAM MAYNER. 

